1. Field of the Invention
The present invention relates to turbine cylinder covers and, more particularly, is concerned with a method and device for inverting turbine cylinder covers.
2. Description of the Prior Art
A high pressure turbine includes a cylindrical body formed from a cylinder cover and a bottom. The bottom forms the foundation for the turbine, and the cylinder cover is bolted atop the cylinder cover for forming a sealed enclosure. Attachment devices, such as eyelets, are positioned on the cover for lifting purposes. Two steam inlets are disposed atop the cover for allowing steam to enter the body, and four steam outlets are disposed on the bottom for allowing steam to exit the body. Pipes are attached to both inlets and outlets for passing the steam therethrough. A turbine shaft is positioned longitudinally inside the turbine body and includes turbine blades attached circumferentially around the shaft. When operational, the steam enters the steam inlets, turns the turbine blades, and then exits the body via the outlets as is well known in the art.
To invert the cylinder cover for inspection, the bolts are removed, and the cylinder cover is detached from the bottom and placed on a floor by means well known in the art. A crane, which includes two hooks, is positioned adjacent the generator for inverting the cylinder cover. In power plants, where most turbine generators are located, the crane typically includes a large hook and a small hook for lifting the cover. As is well known in the art, present devices and methods require two hooks to invert the cover. The small hook, however, is insufficient for cylinder cover inversion because the attachment devices of the cylinder cover are positioned so that the small hook must support a weight heavier than its capacity. To overcome this deficiency, a portable crane with an adequate hook should be temporarily used to supplement the large hook of the existing crane. The cover may then be lifted and inverted.
Although the present device and method are satisfactory, it is not without drawbacks. Installing such a temporary crane is costly and time consuming because it requires acquiring and installing this temporary crane.
Consequently, a need exists for an improved device and method for lifting a turbine cover.